["Journal of Applied Social Psychology, EarlyView. ", "\nABSTRACT\nAdopting a social norms perspective, this research examines how individuals' perceptions of others' attitudes toward AI shape their own willingness to adopt AI. Across an online survey (N = 309), three laboratory experiments (Study 2: N = 261; Study 3a: N = 247; Study 3b: N = 253), and a single‐paper meta‐analysis, individuals were found to consistently underestimate others' positive attitudes toward AI. This systematic underestimation, in turn, reduced their intentions to adopt AI, yielding medium‐sized effects. Moreover, this relationship was partially mediated by outcome efficacy and perceived risk across multiple contexts. Theoretically, the findings highlight normative misperception as a key social mechanism in AI adoption. Empirically, they suggest that correcting biased social perceptions may promote AI acceptance via social‐norm‐based interventions."]